The present dissertation expounds the research results on the mystic contents and symbolism in Miró's work, based on the detection and interpretation of the symbols and symbol codes of metaphysical, religious, spiritual and mythical traits in the period between 1922 and 1942. This chronological period, which takes as a starting-point the interpretations of the first painting with mystic content, La Masía, involves the phases of constitution, development and consolidation of the selected symbols and symbol codes, completing an evolutionary cycle, whose established models are definitely installed in Miró's work of the later decades, reiterating symbols that do not manifest any further evolution from the iconographic or semiotic point of view.This dissertation started from the relevance of certain results in previous investigation, that were exposed in the licenciate thesis entitled: I disegni surrealisti di Joan Miró degli anni venti (Miro’s Surrealistic Drawings of the 1920s), and in the Master thesis La interpretación del simbolismo místico de la obra surrealista de Joan Miró (The Interpretation of Mystic Symbolism in Joan Miro’s Surrealistic Work). Both are the result of the opportunity to carry out an exhaustive investigation in the archives of the Fundación Joan Miró in Barcelona. Initial focusing on the contextualization and the relation between Miró's work and its symbols have clearly highlighted the mystical and spiritual nature of the contents and elements analyzed, thus offering the possibility of an interpretation of Miró's work on various levels, and thereby leading to research into the topic of mysticism, which up to now has partly been dealt with thanks to the insights of specialists which are referred in this dissertation.The first part of this thesis exposes a reinterpretation of Paisaje catalán canvas, in which, after the application of a method named “dislocation of the elements”, a system of signs that has been detected and that reveals the spiritual features of the painting and substantiates new connections with paintings that are directly linked to it: La masía and Tierra labrada.Miró's mystical symbolism expresses abstract concepts that he elaborated plastically, such as the condition of freedom of any being, the links between the tangible and intangible reality, the movements of transition between these two realities and the spiritual elevation experienced by the beings portrayed in the work and pursued by the author himself. The interpretation of determined mystical symbols, codes and contents and the study of their semantic and formal evolution, determined by the processes of synthesis, association, fusion, integration and mutation applied by the painter, are at any moment backed by findings derived from the archival research, secondary sources data, the artist's statements and his sources of mystical-religious inspiration, intellectual and iconographic as well as literary.Considering the relevance and the amount of unpublished research results, the final chapter has been dedicated to the sources of the artist's inspiration in the context of literature. In this chapter is testified how the mystical aspect not only concerns symbolism and Miró's work, but also the Catalan painter's purposes of expression and his artistic process, which have been compared, even by his contemporaries, to those of an ascetic and mystical character.